Ball grinding-mill.



No. 676,254. Patented lune Il, |90|.

` C. HOFMANN. I

BALL GBINDING MILL.

(Application led Sept. 17, 1898.)

(No Model.) l 3 Sheets-Sheet l.

\. fum e SMH@ MALL( W/TNESSES No. 676,254.V Patented lune u, 19m. c. HUFMANN.

BALL GRINDING MILL.

(Application Bled Sept. 17, 1898.)

(No Model.)

WITNESSES.'

YH: Nowms persas co, PNOToJLIrNmWASmNGTON. n.5.

3 Sheets-Sheet 2.

No; 676,254. `Pat'ented lune Il, I90l. C. HUFMANN.

BALL GmN'nlNG MILL.

(Application filed Sept, 17, 1898.)

(No Model.) 3 Sheets-Sheet 3.

UNITED STATES- 1 PATENT OFFICE.

CARL HOFMANN, OF BRESLAU, GERMANY.

BALL GRlNDlNG-MILL.

SPECIFICATION forming part of Letters Patent No. 676,254, dated June 11, 1901.

Application filed September 17, 1898. Serial Nol 691,157. (No model.)v

To `otZZ whom. it may concern.-

Be it known that I, CARL HORMANN, merchant, of Klosterstrasse 66, Breslau, in the Province of Silesia, German Empire, have invented certain new and useful Improvements in Mills, of which the following is a full and clear description.

This invention relates to grinding, crushing, and similar machines of the ball-and-rin g type; and its object is to improve the efficiency of such machines.

In a machine constructed'to embody these improvements the balls are preferably oval and have an oscillatory motion imparted to them in addition to their rotary motion around the ring.

The accom-panying drawings illustrate a machine constructed according to this invention.

Figure l illustrates the machine in longitudinal section. Fig. 2 shows it in plan. Figs. 3, 3, 4., and 5 are representations of the devices for imparting oscillatory motion to the balls. Figs. 6 and 7 are respectively a plan and a side elevation of the mechanism whereby the speed of the machine may be varied.

This mechanism is also shown in front elevation in Fig. 1.

Referring to Figs. l and 2, ot represents the trough-shaped ring, in which the material to be crushed is placed. b is a vertical rotary shaft carrying the four projecting arms c, the

cured to the cups or shells f, which loosely contain the balls e. As shown, these balls are preferably oval.V The cups f are so connected to the links oZ at the points g that they may give and enable the balls to surmount and pass any unusual obstacle contained within the ring.

The device for causing the balls to oscillate across the ring during their rotation therein is illustrated most clearly in Fig. 3. A grooved cam h surrounds the shaft b, and with the groove are engaged the bolts it" t2, which are carried by the arms Zr. These arms are suitably jointed in their lengths and are connected to the links d. Thus upon the rotation of the shaft b the arms c and the balls e are carried around the ring a and cause also the rotation of the arms k. These latter by their engagement with the grooved cam are also reciprocated and cause the oscillation of the balls across the ring.

The cam h may either be fixed or caused to rotate slowly, the latter being preferred, as with a stationary cam the balls would always move across the ring at the same points and unequal wear would result. With a slowlyrotating cam, however, all parts of the ring will be equally worn.

The devices by means of which the desired rotation of the cam may be elfected are shown in Figs. 3, 3a, 4, and 5. Fixed to theshaft b is a sleeve Z, the lower part of which is formed into or is provided with a disk or plate m, carrying the pinion o. This pinion gears with internal teeth formed within a surrounding casing r1, andalso with a wheel p,

-Which is free to rotate upon the sleeve Z.

This wheel is in one piece with a bevel-wheel q, which in its turn gears with a bevel-Wheel r, to which the pinion s is secured. This pinion engages with the wheel t, which is provided with an additional projecting tooth u.

Once during every revolution of the wheel t creasing its speed as the crushing or grinding progresses. A form of apparatus which may be employed is represented in Figs. l, 6, and 7. The main driving-shaft x is provided with fast and loose pulleys of the usual construction and with a vconed pulley m'. From this latter pulley a belt x3 passes to and around the inversely-coned pulley fr?, mounted upon the shaft y, the end of which carries the bevel-wheel y for driving the machine. The belt x3 passes through the beltfork m4, the lower end of which is formed with an extension x5. The boss or support m7 of the belt-fork is mounted upon and is capable of sliding along the square shaft 006.- Connected to the boss is the partial or half nut ICO A to the other.

00B, capable of engaging with the rotary screw :209, by the rotation of which the boss and the strap-fork may be moved along the shaft x6. The belt is thus moved along the coned pulleys as the grinding proceeds, the movement being in such a direction as to increase the speed of the machine. m10 is a guide-bolt attached to the belt-fork. The screwed shaft fr may be rotated by means of a chain or the like from the main shaft When the belt reaches the end of the coned pulleys, the machine is automatically stopped. To return the belt to the other end of the pulleys, a slight angular motion is given to the square shaft :t6 by means of the rod ,a and the lever z. By this motion the half-nut x8 is moved away from the screwed shaft, the forks m4 :1:5 are swung into the position shown in dotted lines, and the belt-fork is free to move along the square shaft. A rack z2 is arranged in gear with a pinion to which is attached a reel or drum having wound around it the cord or chain z3. One end of this cord is attached directly to the beltfork,and the other end passes around al pulley on the opposite side of the mechanism'and is then in turn also at tached to the fork. The rotation of the drum in one direction will draw the fork toward it, and its rotation in the other direction Will cause the fork to move away. The rotation of the drum in the required direction may be effected by raising or depressing the rack z2.

` The dotted lines in Fig. 7 show the positions of the various parts when the belt is free to be moved from one end of the pulleys The extension .605 of the fork is now in engagement with the belt, and the bolt x10, which has before served to maintain tension in the belt, has now left it, so that the belt is slack.

The links d or the cups or casings f may advantageously be additionally connected to the arms c by means of chains or the like.

Having now particularly described and ascertained the natu re of my said invention and in what manner the same is to be performed, I declare that what'I claim isl. In a ball grinding-mill, the combination of a trough-shaped ring, a rotaryT drive-shaft within the same, supporting-arms extending radially from said shaft, depending links piv-V oted to the said arms, grinding-balls suitably supported by said links, and means positively connecting the said links with the drive-shaft for imparting an oscillatoryrmoveinent to the links and balls, substantially as set forth.

2. In a ball grinding-mill, the combination of a trough-shaped ring, a rotary drive-shaft arranged at the center of the ring, arms eX- tending radially from said shaft, depending links pivoted to the said arms at points approximately above the middle of the crosssection of the ring, grinding-balls elongated transversely to the ring, and suitably supported byV said links, and means for imparting an oscillatory movement to the links and balls, whereby the latter are caused to travel in a serpentine pathin the trough of the ring, substantially as set forth.

3. In a ball grinding-mill, the combination of a trough-shaped ring, a rotary drive-shaft,- grinding-balls elongated transversely to the ring, means for imparting rotary motion from the drive-shaft to the balls so as to move them around upon the ring, and means for moving said balls in longitudinal direction, so that a compound movement is imparted to the balls, causing them to travel in a serpentine path around the ring, substantially as set forth.

4. In a ball grinding-mill, the combination of a trough-'shaped ring, a rotary drive-shaft,- grinding-balls in the trough of the ring, means for imparting rotary motion to the balls around the ring, means for movingthe balls in a direction toward and from the shaft, whereby the same are caused to travel in a serpentine path, and means, acting on the latter means, for intermittently changing the path of movement of the balls, substantially as set forth.

5. In a ballvgrinding-'milk the combination of a trough-shaped ring, a rotary drive-shaft,

grinding-balls in the trough of the ring, means for impartingrotary motion to the balls around the ring, means for moving the balls from side to sideof the ring, causing them to move in a serpentine path, and means for gradually increasing the speed of the balls around the ring, substantially as set forth.

In witness whereof I have hereunto set myl hand in presence of two Witnesses.

CARL HO FMAN N.

Witnesses:

HERMAN BoRTsoH, EDWIN WEISS.

ICO 

